There are many instances in which it is necessary to dispense an accurately metered volume of a selected liquid. For example, this need rises in beverage dispensing in that a measured portion of the beverage selected by the customer must be dispensed. In the past, considerable attention has been given to dispensers for alcoholic beverages. In a typical prior art dispenser for alcoholic beverages, the user pushes a button corresponding to a particular beverage, and in response a metered quantity of the selected beverage is dispensed. This concept is desirable because it provides for accurate and rapid dispensing, and in some instances for inventory control. Unfortunately, prior art dispensers of this type are relatively complex. This in turn increases the cost of the unit. Other dispensers are dangerous in that they require pressurizing of the beverage bottle.
Another problem with prior art units is that the controls are, at least in part, electric. Typically, the dispenser includes a dispensing head from which the liquid is dispensed and which contains electrical switches for selecting the beverage to be dispensed. The switches in turn operate solenoids which provide the dispensing control function. Because of the inherent presence of liquid around a bar or other beverage dispensing counter, there is a danger of shorting out the electrical controls.